PreservativeWorks with gluconolactoneIn every formula

Sodium Benzoate

Sodium benzoate · INCI Sodium benzoate

If you have looked sodium benzoate up, you have probably read something alarming about benzene. That story is not invented, and it is also not about products like ours. Rather than hope you do not check, here is the whole thing.

You may have read that this turns into benzene. There is a real story behind that, and it does not apply to our products. Here is why, in full.

Sodium benzoate, the second half of the preservative system in every formula.
Sodium benzoate, the second half of the preservative system in every formula.

What it is

Sodium benzoate is the salt of benzoic acid, which occurs naturally in cranberries, plums and a number of other fruits. In our formulas it is one half of a two-part preservative system: it works with the gluconolactone listed further up, and together they keep the product free of bacteria and mould for its life on your shelf. Neither does the job alone, which is why they are always used as a pair, and why the two ingredient pages here are really one story told twice.

We chose this system because it is among the gentlest available and it is accepted under the organic cosmetic standards. It also has one requirement worth knowing about: it works best in a mildly acidic product, which ours are, and which is also the pH your skin prefers. That is a happy alignment rather than a compromise.

What it does in our formulas

One thing, and it does not work alone.

01

It keeps the product safe, with help

Sodium benzoate works in partnership with the gluconolactone further up the list. Together they hold the product at a mildly acidic pH and make it inhospitable to bacteria and mould. It is one of the gentlest preservative systems available, and it is accepted under the organic cosmetic standards, which is a large part of why we chose it.

Well characterised

What the research does not show

Two things get said about sodium benzoate. One is a real story taken out of context. The other is the far more dangerous idea, and it is the one nobody worries about.

Marketed as It turns into benzene, which causes cancer
This deserves a full answer rather than a brush-off. The story is real, and it comes from soft drinks. Benzoates can react with ascorbic acid, which is vitamin C, to form traces of benzene, and it takes warmth, light and metal ions to get going. It was found in fizzy drinks in the 1990s and it was a genuine problem there. It has nothing to do with our products, because our products contain no vitamin C. Not a trace. Without it, the reaction simply has nowhere to start.
Marketed as Preservative-free products are safer
The opposite is true, and this is the claim that actually worries us. Anything with water in it will grow bacteria and mould, and a cream growing mould on your bathroom shelf is a real risk in a way that a well-studied preservative is not. Brands claiming to be preservative-free are usually preserving with something they would rather not call a preservative. We put ours on the label and wrote it a page.

So: a gentle, well-studied preservative, doing an essential job, in a formula that gives the benzene reaction nothing to work with. We would rather explain that in full than leave you to wonder.

On the label and in the range

Sodium benzoate appears in every one of our formulations, toward the end of the ingredient list, and it works with the gluconolactone sitting further up. Read them as a pair rather than as two separate ingredients. The exact percentage is published on each product page, as it is for everything we use, including the parts most brands would rather you did not dwell on.

Is it suitable for me?

Sodium benzoate has been reviewed by the independent expert panel that assesses cosmetic ingredients and found safe as used. It is well tolerated, suits a vegan routine, and carries no restrictions of concern under UK or EU cosmetic law at the levels used in leave-on products. Allergic reaction to it is uncommon, though as with any preservative it is not impossible, so if your skin reacts easily a patch test first is sensible.

Vegan-friendlySensitive-skin suitableNo known safety concerns

As with anything new, if your skin reacts easily it is worth patch testing first.

Formulation Clear
Formulation Clear
Science led
Science led
Gentle, skin friendly
Gentle, skin friendly

The research behind this page

We review the published literature. We do not conduct the studies below.

  1. Nair B. Final report on the safety assessment of benzyl alcohol, benzoic acid, and sodium benzoate. Int J Toxicol 2001;20(Suppl 3):23-50.
  2. Cosmetic Ingredient Review Expert Panel. Amended safety assessment of benzoic acid, its salts and esters.
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